1. Field of the Invention
The present invention relates to a drum type washing machine, and more particularly, to a device for attenuating vibration of a drum type washing machine.
2. Background of the Related Art
In general, the washing machine removes dirts and contaminants stuck on laundry by chemical decomposition and mechanical impact. Of washing machines, the drum type washing machine has an increasing demand because the drum type washing machine, not only permits to reduce a total height in comparison to a pulsator type washing machine in which an inner tub, a washing tub, is rotated in an upright position, but also permits to increase a washing capacity, and causes almost no problem of laundry entangling. A system of a related art drum washing machine will be explained with reference to FIGS. 1 and 2.
The related art drum washing machine is provided with a body 10, an outer tub 11 supported by dampers 41 and springs 40 in the body, and a cylindrical inner tub 12 rotatably mounted in the outer tub. The inner tub receives a driving force from a driving part for washing the laundry. The driving part has a pulley 33 around an inner tub shaft 34, a motor 30 mounted on one side of a lower part of the outer tub, and a belt 32 connected between the pulley and the motor for transmission of a power generated at the motor to the inner tub shaft. Though not shown, there is a driving part system in which a power generated by a rotor(not shown) and a stator(not shown) is transmitted to an inner tub shaft 34 directly, and other driving part system in which the power is transmitted to the inner tub shaft in a variety of methods.
The operation of the related art drum washing machine will be explained. Upon introducing the laundry into the inner tub 12 and starting washing, the washing proceeds from washing cyclexe2x86x92rinsing cyclexe2x86x92spinning cycle in succession until all the preset cycles are completed. That is, when the washing is started, a water supply device is put into operation, to supply washing water through a water passage 20, until the supplied water fills up to an appropriate level when the water supply is stopped and the driving part makes reverse and regular direction rotation, repeatedly. The reverse and regular direction rotation of the driving part is involved in speed reduction by speed reducing means, and applied to the inner tub 12. Then, the washing of the laundry is made both by impact caused by water circulation occurred as the inner tub is rotated in reverse and regular rotation directions and decomposition by detergent. Upon completion of the washing cycle, a rinsing cycle is carried out in the same process as the washing cycle, and upon completion of the rinsing cycle, the process proceeds to the spinning cycle right away. Upon starting the spinning cycle, the water filled in the inner tub 12 is drained completely through a drain hose 54 by a drain pump 31. In this instance, as the driving power of the driving part is transmitted to the inner tub 12 as it is without speed reduction, a centrifugal force caused by high speed rotation of the inner tub 12 extracts water contained in the laundry, to dehydrate the laundry. However, the drum washing machine, a horizontal type of washing machine, is very sensitive to vibration compared to the pulsator type washing machine, an upright type of washing machine, in the spinning cycle, because the drum washing machine, a horizontal type washing machine, having the inner tub 12 disposed in a horizontal position, and the drain pump 31 and the motor 30 mounted on a rear surface of the outer tub, to make a front portion of the outer tub relatively less heavy, may cause heavy vibration. And, the outer tub 11 disposed in a front portion of the body receives a vibration of the inner tub caused by eccentricity of an inner tub rotation coming from unbalanced settling of the laundry in the inner tub 12 during spinning 12 directly, to draw a large ellipse as the outer tub 11 rotates. That is, if a vibration is occurred when the inner tub 12 carries out the washing and the spinning as the inner tub 12 rotates, and the vibration is transmitted to the outer tub 11 directly without attenuation, there is cases when the vibration is matched with a natural vibration of the outer tub, to cause a resonance. Eventually, as shown in FIGS. 2A and 2B, the following vibration attenuator is used for reducing such a vibration.
The first vibration attenuator has pairs of dampers 41 each pair on left and right sides of the body 10 connected between lower portions of an outer circumference of the outer tub 11 and lower portions of the body 10, for attenuating vertical vibration among vibrations occurred at the inner tub 2 rotates.
The second vibration attenuator has a plurality of holding springs 40 connected between an upper portion of the outer circumference of the outer tub 11 and an upper surface of the body 10, for restoring displacement absorbed by the damper 41 caused by the vibration coming from rotation of the inner tub 12.
The third vibration attenuator has weights for increasing weight of the outer tub 11 to reduce a natural frequency of the outer tub itself, to match the natural frequency of the outer tub 11 with a frequency occurred at the inner tub 12 at an initial stage of the spinning cycle when the rotation speed is low. Accordingly, at starting of rotation of the inner tub 12 in the spinning, the frequencies are the same already, and there is no chance when the natural frequency of the outer tub 11 becomes the same with the frequency of the inner tub 12 during the spinning, to prevent the resonance in advance. That is, weights 42 of cast iron or concrete are provided to an upper surface and a lower surface of the outer tub, not only for increasing the weight of the outer tub 11, but also balancing weight of the motor 30 and drain pump 31 mounted on the outer tub.
However, the third attenuator has the following problems.
The cast iron or concrete used for attenuation of the vibration increases a production cost, as well as weight which causes a problem in transportation of the drum type washing machine.
And, reinforcement design for other related components for the increased weight causes an increase of the production cost.
Accordingly, the present invention is directed to a device for attenuating vibration of a drum type washing machine that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a device for attenuating vibration of a drum type washing machine, which can reduce a transportation weight of the drum type washing machine and save a production cost.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the device for attenuating vibration of a drum type washing machine includes a balance chamber provided to an outer tub for temporary storage of extracted water in spinning for serving as a weight for attenuating vibration of the outer tub, means for supplying the extracted water to the balance chamber in the spinning, and means for draining the extracted water from the balance chamber to outside of the washing machine on completion of the spinning.
The means for supplying the extracted water includes an extracted water flow passage for supplying water in the outer tub to the balance chamber on the same time with draining to outside of the washing machine, and an extracted water pump connected to the extracted water flow passage for pumping the extracted water for smooth drainage of the water.
The means for draining the extracted water includes a drain water flow passage for draining the water from the outer tub and the balance chamber to outside of the washing machine, and a drain water pump connected to the drain water flow passage for pumping the water for smooth drainage of the water.
In another aspect of the present invention, there is provided a method for controlling washing of a drum type washing machine comprising the steps of washing, rinsing, and spinning in succession, wherein the step of spinning includes the step of supplying water to a balance chamber.
The method for controlling washing of a drum type washing machine further includes a step of draining water remained in the washing machine after the step of spinning.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.